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Stock-Based Compensation - Additional Information (Details) - USD ($)	1 Months Ended			3 Months Ended		6 Months Ended
	Feb. 28, 2019	Jul. 31, 2018	Feb. 28, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from exercise of stock options						$ 7,000
Proceeds						$ 198,000	$ 301,000
Issuance of common stock for services, shares				113,136	75,183	113,136	75,183
Issuance of common stock for services, amount				$ 311,000	$ 302,000	$ 311,000	$ 302,000
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options exercised				1,681	0	2,451	0
Proceeds from exercise of stock options					$ 0		$ 0
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued upon vesting of restricted stock units				85,609	0	85,609	0
Performance-Based Restricted Stock Units (PRSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Granted		903,374
Number of Shares, Outstanding				861,989		861,989
Number of shares issued upon vesting of restricted stock units				0	0	0	0
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued under ESPP	83,046		68,589
Purchase price	$ 2.39		$ 4.38
Proceeds	$ 200,000		$ 300,000